Dissolved Barium and Particulate Rare Earth Elements as Tracers for Shelf-Basin Interaction in the Arctic Ocean

This study gives an outlook on the usability of dissolved Ba and particulate rare earth elements as oceanographical tracers in the Arctic Ocean. It is integrated into a sub-project focussing on tracers for the identification of freshwater sources of the European integrated project DAMOCLES (Developing Arctic Modelling and Observing Capabilities for Long-term Environmental Studies). From Polarstern expedition ARK-XXII/2 in summer 2007, dissolved Ba and particulate REE were analyzed in the Barents, Kara, Laptev seas, the Eurasian Basins and the Makarov Basin up to and beyond the Alpha and Mendeleyev Ridges. In chapter 2 I discuss Ba as a tracer in discerning Eurasian from North American runoff together with well established water mass tracers (salinity, d18O, nutrients). In chapter 3 I investigate how dissolved Ba of intermediate and deep waters may be used together with Al and silicate to describe exchange of waters from the shelf seas with the interior basins. In chapter 4 I describe REE patterns in suspended particulate matter from surface water in a wider context illustrating the contrast between the remote Southern Ocean and the nearly land locked Arctic Ocean.